The applicants have previously proposed choke valve apparatus in which an operation shaft connected to a choke valve provided in an intake passage of an internal combustion engine and a driving shaft connected to a pulse motor are interconnected through an intermediate torsion spring and are engaged with another through circumferentially disposed front and rear pawls for being feed-driven only in a regular direction of rotation of the driving shaft, the arrangement being such that, by imparting a reverse direction of rotation and then a regular direction of rotation from the pulse motor, the choke valve is given an initial standard position setting, then a starting position setting, then an open-degree position after completed engine firing is carried out by a regular direction of rotation of the motor at a predetermined high speed and for a fixed length of time. With this arrangement, however, there is the deficiency that because the choke valve is always driven at a fixed speed to the open degree position, delay in fuel supply may arise especially upon engine starting at low temperature. Accordingly the engine operation may not be smooth and may be unstable and lead to engine stalling.